The Multigrid Workbench: Restriction

The restriction transports the residual of the fine grid to the coarser grid. The typical process averages the neighboring vales according to a stencil, like

This is the so called full weighting restriction, as used in the example of the multigrid workbench.

Alternatives include

In general, the choice of restriction as the transpose of interpolation plays an especially important role in the praxis and theory of multigrid methods.

Ulrich Ruede , Thu Feb 2 21:05:56 MEZ 1995
Updated by Craig C. Douglas